Device for preventing injury to pipe coatings



Aug. 5, 1952 G. N. SCOTT DEVICE FOR PREVENTING INJURY TO PIPE COATINGSFiled Oct. 27, 1947 Snnentor Gonna N. Sea-r1: flaw: m. m. muz pfilattorney Patented Aug. 5, 1952 DEVICE FOR PREVENTING INJ RY T turn 7COATING Gordon N. Scott, Beverly Hills, Calif. Application October 27,1947, Serial No. 782,338

. l This invention relates ing injury to bituminous pipe coatings duringhandling and transportation of the coated pipes and the construction ofpipe lines whether the coating be applied .at a central plant or in thefield in an over-the-trench operation.

At the central plant where the pipe is cleaned and coated, it may bestockpiled or at once loaded on trucks, transported to the field andstrung along the right-of-way where it is welded together and placed onskids preparatory to cleaning and coating the welded joints after whichthe pipe islowered into the trench and the trench back filled. In theover-the-trench coating'operationthe pipe is made up and placed'on skidswhich span the trench. This operation is followed by usually twotravelling type machines which clean, prime and coat the pipeline whichis then either laid directly in the prepared trench'or upon the skidswhich span the trench. In the latter step, opportunity is afforded toinspect and to repair the coating before the pipe is lowered.

In the various steps in these several operations the coating may beabraded and require patching before the lowering is done which slows andadds to the cost of construction.

Factory coated pipe for transportation is often nested on a fiat-bedtruck or, particularly in the longer lengths, laid on bolsters oncompanion truck and trailer and the loaded pipe securely held to thebolsters by chains.

, the coated pipes so that the bolster contacts the coating at the lowertier of pipes, while the cinch chain contacts the coating on the upper 1Claim. (01. 138-61) to a device for prevent- While a set of Q theuncoated ends of pipe can be placed on the tier. Notwithstanding thecustomary padding v of bolsters and bolster chains, the coating is oftenabraded at such points of contacts, espe-' cially when the haul is longor rough.

The, pipe lengths are welded together in the field and placed on 4-inchby 6-inch skids placed across the pipe trench and usually so locatedbetween the welded joints to minimize stresses on the welds. The made uppipe on skids, which may be one or more miles in length, expands andcontracts with changes in temperature between day and night and inextreme cases may wander completely off the skids to the disadvantage ofthe coating.

Pairs of skids are also employed in a formation to support the pipelinewhere the portion a laid emerges from the back-filled trench and soextends to the skidded over-the-trench position. At all such skiddedpoints the coating is susceptible to damage notwithstanding ordinaryefforts to pad the sk ds.

In the field application of coatings on made up pipe, one practice is toso govern the coating operation as to be assuredof perfection in .thecoating so thatthe lifted pipe is lowered directly into the trenchbehind the coating machine. Another. practice is to return the elevatedpipe after coating to skids for inspection and repair before lowering.Owing to the general unsatisfactory results of padding, some operatorscompletely ignore padding and patch the resulting coating damage priorto layin along with'the general repair work which is done by a crew justahead of the lowering-in gang.

Padding at bolsters and chains is accomplished by use of scrap rubber orother similar materials appropriately placed. For padding kids burlapsacks filled with straw or sand are in prevalent use, but this type ofpadding has many disadvantages. Weathered sacks or sacks of poor qualityreadily rupture and spill their contents and become of little or novalue. Furthermore, frictional forces involved are such as to cause thepipe, moving laterally on expansion, to carry with it padding and skidso that on later contraction, a length of pipe falls with damage to thecoating into the trench.

The present invention provides a guard of wide applicability forpreventing iniury to the coating in stockpiling, in. transportation andin skidding over-the-trench pipelines.

' The'guard 'of my invention is essentially a short incomplete or opentubular section formed from spring steel or other material havingsuitable rigidity and flexibility to a radius equal to or slightly lessthan the outside radius of the coated pipe and encompassing at leastone-half, and preferably two-thirds, of the circumference of the coatedpipe which it is adapted to protect.

The principal object of my invention is to provlde a device to protectagainst damage during transportation, handling and the like to thecoatmg applied to a pipe.

An important object of my invention is to provide a guard whichinaddition to preventing abrasion to the coating prevents the coating frombecoming unduly thin at the area of contact with a skid by distributingthe stresses uniformly and safely minimizing same.

Another object of my invention is toprovide a guard which may be easilyand rapidly applied to or removed from the pipe, permitting salvage orprompt change in location along the coated pipe. I

Another object of my invention is to provide a guard which will stay onthe coated pipewhen the pipe, is lifted b sling or end hooks or when thecoated pipe is elevated for any reason during construction or before itis lowered to skids behind the over-the-trench coating operation.

Another object of my invention is to provide a guard having a smoothsurface on the portion which is adapted to rest on the skid whichpermits the pipe, on lateral expansion movement, to slide along the skidwithoutcarrying the skid with it, thus saving otherwise possible largelabor costs of repairing coating or trench destroyed by the pipesmovement.

Another object of my invention is .tOfPIOVidE} a:

guard having simplicity of design and flexibility" V which will permitnesting of the guardsso that many units may be nested with great economyin space, may be thus shipped; handledv onstored. at minimum cost.

Another object of my, invention is to provide-a guard in which theends-and edges are chamiered t'o;.insure no. indentation.or.v otherdamage to the coating in the; event :of'freadjusting of the guard,about: the; coating due to. any misalignment,

Another objectiof myzinventiorr 152130 provide aguardtwhich:is-economicalito construct. The low cost of the guard otmy.invention permit-sabandoningzzthe guard? in; the ground, as, for:example, in: removing a; lowering-in. sling when the pipe is laid; in.the. trench which often requires time to belljehole under the pipetofree: the. sling pinned to; the ground; by the lowered. pipe.Uccasionally in pipe-line construction;conditions. are encountered whereit is desirablejt'ogive:rnore or less permanent mechanical.reenforcement to the coating: and; in such; cases guards may be used toadvantage. Examples: which; will be recognized by, those skilled inthearts of such uses. are in fbrcingpipes through casing atroadcrossingsand the like, at. bored-concrete wells c-r embankments,imparvicularly rocky. areaszwhere proper dressing or the trench bottom;is impractical.

Anotherbbject of my: invention istoprovide a gnardiwhich' is" simple in.design andwhich makes ior minimum cost'oifabrication, thus I enhancingthesavingspossible in usein the variety of many of which haveherleinaheenoutlined, such as saving in labor and'equipment: forneedless repair cfthe-pips ocating".

' Myin-vention; hasmanyother objects, advantages, and features, some ofwhich; with the foregoin will be. set; forth. in the followingdescriptiomwhere lishall" outline oneform of my invention,which;Ifhaveselectedtior illustration in the drawings: accompanying and.forming a part of the present specification lftieierringto the;drawings;

Fig; l is a: perspective'view of the guard of my invention;

2:isa schematic view ot 'a section of earth showing pipe line:trenchalong which a coated pi-peline-is protected; by-the. guard of inven--tion, which guard is interposedbetween the coatingva-nd supportingwoodtskids; and

Fig. dis a. cross--sectiozial. view ofpi'pe-loaded ont-he: bolster of:a, truck showing: the-use of the guard: of: my invention.

Referring-to; the; drawings, the numeral m indicates the guard of myinvention, which may be constructed from hard tempered, high. carbon,

cold rolled'strip or, sheet. steel, or other suitable material, that is,materialfwhich; has in suitable combination bothi rigidity andflexibility and which is a semi-tubular section, that is, longitudinallyopen, with. a. principal radius equal to tl-"iatr of the coated pipe,which it is adapted to protect; but preferably with the upper portionl.l formed one, slightlydiminished radius with respect to the radius ofsaid coated pipe.

Asshown iirFig. 3:, in order to have theedges of the: guard l0- lie. intricuspidal areas between stacked pipe, theguardsshould encompass moreit enables the guard to remain on the coated pipe when the pipe islifted or when the made-up pipe slides on the skid due to expansion ormovement.

The length and thickness of the guard It] will obviously depend upon thediameter and weight ofgthe pipe with which the guard is used, upon thephysical characteristics of the protective covering' on said pipe, andupon the distance or span between the adjacent guards. This length is ofthecrdenof approximately threetimes the-diameter: of the; pipe: in.connection; withwhich the guardiisadapted to beused.v

The; ends I-2qand; horizontal: edges: l3-of the guard it maybe: slightlyflared, but-preferably are rounded-orchamieredtoJpreVent sharp; edgesfrom. injuring the: pipercoating and to facilitate removal.

IhjEig. 2 the guardi'til isshownzin position: about the coated; pipeHi;v resting, on. the skids l 5- which are set across the trench l6. Thecross-skids H are employed. to support the pipeline which ispartiallylaid and partially supportedabove the ground level.

In, Fig. 3 theguard lllfis shown in various positions about the:stacked. coated pipes.- 2!lto protect the coating: fromdeformationorabrasion during transit at thebolster. 2.:tandwhere thecinching chain:v 2;2=b'ears against the coating.

From theforegoing.- description taken in connection with the:accompanying drawings, the uses; advantages, and operation of the guardof my inventionwill be readily understood. by those skilled in the art.to: which the; invention. appertai-ns. While: Izhave: described the formof my invention which -1- nowi consider. to be the best embodimentthereon-1- desire: to; have it under stood that the: article shown ismerely illustrative; and that the invention isnot to be limitedto'the'details disclosed herein, but is to be accorded the-full scope ofthe appended claim.v

A guard for protecting externally coated. pipe, comprising: a generallytubular sheet metal section, having opening along its length defined ynerallyparallel longitudinally extending edges; theradius: of, curvatureotthoseportions of. the section: adjacent each longitudinallyextendi-nggedgerbeihg less thanthe principal, radius of: curvatuneof theremainderofthe' section, the circumi-erentiallengthof said: sectionbeing equal to approximately two-thirds of? the ciroumference oi a,circle having a, radius: equal. to said principal radius of curvature;theend edges andsaid longij. tudinally extending edges-being chamferedfrom the innersurfa-ce-ofthe: section tofacilitate removal-ofthesectionafrom' a; pipe.

GORDGN N. SCOTT;

REFERENCES- CITED The following, references are .011 record in the fileof this patent:

UNITED STATES" PATENTS

